I have two batteries for my e830W -- one original; another OEM purchased with the PDA.More often that not, when I change-out the batteries (i.e., exchange a charged for a rundown battery), my e830 "locks up" (black screen) and can only be re-started by doing a "hard reset." This, of course, is a pain. Even though I keep most programs on CF or SD cards, it still requires time to re-setup the PDA as I want it. I shut down the PDA before changing batteries, but the problem seem to occur whether or not any programs are running at the time of the battery change-out.

Are any other e830 / e800 owners having this problem? Any "fix" known?

This definitely should not happen. It sounds like the backup battery has died-- it maintains your data for approximately 10 minutes when the main battery is removed. As a workaround, you might try connecting power to the PDA before pulling the battery.